A number of power adapters are widely known in the prior art for use in supplying power to a variety of portable electronic devices, including computers, tablets, cell phones, smart phones, media players, and the like. The power adapter receives power from an external power source supplying alternating current (AC) voltage, and converts it to direct current (DC) voltage for use by the device for operations or for recharging an internal battery. Power adapters may be limited to a single type of external power supply and may be device-specific, while others have interchangeable plugs or other input means to be used with multiple power supply sources, or that provide alternate outputs. Examples of such devices include the power adapters disclosed in U.S. Pat. Nos. 5,019,767; 5,684,689; and 6,086,395, and U.S. application Ser. No. 12/778,738, the specifications, drawings and disclosures of which are incorporated herein in their entireties by specific reference for all purposes.
Many portable electronic devices also can be powered through a Universal Serial Bus (USB) port, or similar port or connector, on a computer or similar apparatus. The USB port, for example, can be used to exchange data with the portable electronic device as well as supplying power. Detailed descriptions of the USB interface port are disclosed is U.S. Pat. Nos. 5,8984,086 and 6,086,430, which are incorporated herein in their entireties by specific reference for all purposes.
Many users have multiple devices that require frequent charging. These often require different, device-specific adapters, or multiple cables, which require the user to carry separate adapters around for each device. In addition, in many locations the number of plugs or connectors providing an AC power supply may be limited. With specific regard to USB-powered devices, while such a device can be “daisy-chained” through a USB port on a laptop computer or similar device that is, in turn, connected through its own adapter to an AC power supply, the power supplied through the USB is often restricted, leading to long recharge times for the USB-powered device. This is especially true for newer devices that require substantially more power than that provided by standard USB interfaces. Other use of the USB port also is preempted during that period.
While a number of power adapters are being fashioned with multiple alternative outputs, such devices are typically large and cumbersome, or require the user to select between the outputs. In addition, such adapters do not help users of computing devices supplied by other forms of power adapters. Accordingly, what is needed is a device that can be attached to existing power adapters by a user to provide a power supply to additional devices other than the main device receiving power from the power adapter, simultaneously with the power being provided to the main device without interfering or affecting that power.